[mlag]

I think you need to classify a bit:

1. Protective filters is a debate between physical protection and image quality and circumstances/ environment. Open for debate...

2. Filters for the film era : UV and IR blocking filters improved colors on film, and I remember some yellow-orang’isch for black and white (? Feel free to help here, not my strong point bw film) , these became useless on digital because the UV-IR-protection sits on the sensor and bw is postprocessing...
Colored filters to get for instance blue or red sky effects (typical with gradation from top to bottom) can be easier done in postprocessing on digital, so I put them under 2 (but can work on digital if you insist)



3.filters with a purpose ( valid on a digital sensor unlike 2)

• ND neutral density, to reduce light and allow for extreme long exposures, like to freeze moving water....etc...
• Polarisation to avoid reflections
• Starburst (metal crosswires) to get light star effects
• Filters to do IR or UV photography blocking visible light (and allowing UV or IR contrary to those under 2)
• One could add macro magnifying "filter” because they mount like filter (but are lenses...)
• ...

So category 2 got useless for digital but some still use film so even these remain in use... the others are still in use.

[Robert N]

Personally, I would only use filters for protection in adverse weather conditions such as salt water spray or blown grit/sand. Saying that, I would be reluctant to expose the camera to severe blown grit. My reasoning for generally not using filters is based on:
1. I have experienced artefacts from filters, such as 'double glazing' type reflections, under certain lighting conditions.
2. Techniques such as bracketing exposures and blending can be utilised instead of using graduated filters.
3. Multiple exposures and photographing in low light can be utilised to create different effects of moving water, avoiding using ND filters.
4. I appreciate glare from polarising filters cannot be replicated by post production adjustments. However the orientation of the camera to the sun and sky coverage by the lens, with regards to differing sky darkening effects, limits the situations where the filter can be used effectively.
5. It is not unknown for screw-in filters to seize in the lens screw thread.
6. External square filters are can introduce lens flare as they are not shaded by the lens hood.
6. I always use a lens hood to protect the lens front element.

This is not an 'anti-filter' argument, but just my own reasoning for only using a protective filter under extreme weather conditions.

[abruzzi]

I remember some yellow-orang’isch for black and white (? Feel free to help here, not my strong point bw film)

These were frequently called "contrast" filters because they shifted the representation of certain hues in the translation to B&W. Yellow 15, Orange 21, and Red 25 progressively darkened the skys (blue) while having less impacy on the ground. Some B&W shooters I know have a yellow 15 on their lens all the time. Yellow Green (forget the number) could be used with caucasion faces, green to lighten foliage, blue to turn your red-rose black (a color filter lightens the things with the same color and darkens things on the opposite side of the color wheel.) I'm sure these things can easily be done in photoshop, unless like me, you want to capture the image in-camera.

[kmccanta]

I didnt notice anyone mention that UV filters reduce people fringing.
Maybe I am wrong here but my kid showed me their attempts to get birds with mt old k30+m200.

Without the filter the fringing was really bad shooting through a tree at a bright sky. With the filter, the fringing was much reduced.

[que es tu]

I didnt notice anyone mention that UV filters reduce [/HL]people fringing.
Maybe I am wrong here but my kid showed me their attempts to get birds with mt old k30+m200.

Without the filter the fringing was really bad shooting through a tree at a bright sky. With the filter, the fringing was much reduced.

I personally like people who are on the fringes, much more interesting than old sticks in the mud. That’s why I don’t use UV filters.

[totsmuyco]

I use UV filters on all my lenses just for protection. I remember one Holy Week when I was out taking pictures and I didn't notice a kid trying to poke my lens with a barbecue stick out of his curiosity. Can you imagine the damage if I didn't have any protection on my lens? My lens would've been a goner. For protection from stupid people, I'd say put it on.

[madison_wi_gal]

I use UV filters on all my lenses just for protection. I remember one Holy Week when I was out taking pictures and I didn't notice a kid trying to poke my lens with a barbecue stick out of his curiosity. Can you imagine the damage if I didn't have any protection on my lens? My lens would've been a goner. For protection from stupid people, I'd say put it on.

The kid is also lucky your lens was protected!